It is a challenge for every urban driver - finding reasonably priced parking. But before taking another loop around the block, it might be wise to consult a new mobile app.

Parking Panda is a parking reservation service that allows drivers to find and book parking spots directly through their smartphones. It also lets those with empty driveways earn extra cash by renting theirs out.

"We do everything from the driveway behind your house, to school and church parking lots, all the way up to 10-story commercial parking garages," said Nick Miller, co-founder and CEO of the Baltimore-based company.

The app displays parking spots available nearby, which can then be reserved and paid for instantly. Daily rates for parking spots are approximately 15 to 20 percent cheaper than the average rates in most cities, according to Miller, and include both private parking spots, as well as commercial lots and garages.

"Dinners in Nob Hill are better covered by a private driveway, but a meeting for work in SOMA is better covered by a commercial garage - so you really need both," Miller explained, referring to San Francisco neighborhoods.

The service, available for the iPhone and on the web, also allows those with empty driveways to rent out their unused spots - an idea that Miller said was inspired by the difficulty he faced in renting out his unused parking space in college.

"We had a townhouse with a driveway, but no car. It was empty all the time and not used," he said. "I thought there had to be a better way to solve the problem."

Those renting out their driveways can earn several hundred dollars a month depending on the city and area they live in, according to Miller.

The company has also helped schools and churches rent out their unused lots for local events.

"The Preakness horse races is one of the biggest horse races in the world and we helped a school sell its parking lot for the one-day race and we made close to $5000 for the school in a single day just by selling its parking space," Miller said.

The company collects a fee between 15 to 20 percent for each transaction.

Over 20,000 parking spaces can be reserved through the app in Baltimore, Maryland, Washington, DC and San Francisco, California.

In the next few months, the company plans to expand its service to Philadelphia, Pennsylvania, Boston, Massachusetts, Los Angeles, California and Austin, Texas.

Drivers outside these cities are still able to access information, such as pricing, for over 500,000 parking spaces in lots and garages near them, however they are not yet able to reserve them within the app.

Looking ahead, the company also plans to release tools and analytics for commercial parking lots and garages that will help them set pricing, in a similar way to how hotel rooms or airline tickets are priced.

Similar services include Parkatmyhouse.com, based in Britain and ParkWhiz, based in Chicago.